[TowerTalk] 80m vertical gain array

[K4SAV]

That water tower is going to be a major player in determining how any 
kind of vertical or sloping antenna is going to work.  Without some very 
detailed analysis or measurements, anything you do is going to be trial 
and error.  It is very likely that the water tower will act as a 
reflector, and if you just put up a half wave sloping dipole, you might 
get good performance, maybe a cardioid response.  Two dipoles, one on 
each side of the tower might provide full 360 degree coverage.  My guess 
is that a dipole on one side of the tower will not have a large effect 
on the other dipole on the other side of the tower.

If you try to make a multi-element wire beam off one side of the tower, 
I think the tower will mess it up.

I would not recommend a sloper (quarter wave wire).  This will require a 
huge amount of tial and error testing to get it to work correctly.

Jerry, K4SAV

Robert Thain wrote:

>'allo
>
>I'm looking to install an 80m directional array for
>the ARRL contest.
>
>I will be operating from a watertower, which is about
>130ft high. (see qrz.com F6KCP for a photo.)
>
>There is not a great deal of land around the base of
>the tower, but I can talk to a neighbour and use his
>garden , He is in the direction of the states (Short
>path).
>
>I can easily in stall a vertical dipole or sloper. I
>was thinking about adding a director or reflector or
>both.  Or may be a 2 element phased array.
>
>Whatever it is has to be simple to install and simple
>to get working and relatively fool proof. 
>I am willing to give spend 1dB in gain for a simple
>design.
>
>If I use slopers , is the 'boom length' from the
>middle / feedpoint ?
>
>What will be better than just a 1/2wave sloper but
>easy to install and get working ?
>
>Thanks and CU on 80m in the ARRL test.
>
>Robert F5VHN (F6KCP) f5VHN(at)yahoo.com (at)=@
>
>
>
>
>
>
>		
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